Biomedical subjects

Sung Hee Hwang

Publications and source records attributed to Sung Hee Hwang.

5 recordsLinked to original sources

PubMed2006

Solid-phase combinatorial approach for the optimization of soluble epoxide hydrolase inhibitors.

A 192-member library of N,N'-disubstituted urea inhibitors was synthesized by a solid-phase method. The ureas were tested for their inhibitory activities against recombinant human soluble epoxide hydrolase. Simple carbocyclic or para/meta-substituted phenyl groups showed inhibition potencies that were equal to or greater than adamantane-based sEH inhibitors, while the presence of bulky or ionizable groups close to the urea group dramatically decreased their activities.

Combinatorial Chemistry Techniques↗

PubMed2004

OBOC small-molecule combinatorial library encoded by halogenated mass-tags.

[reaction: see text] A bromine-/chlorine-containing mass-tag encoding strategy for a small-molecule OBOC combinatorial library is reported. The resulting MALDI FTMS isotope pattern of each tag clearly defines the component building blocks of each "hit" bead in an 1890-member demonstration library screened on-bead for binding against streptavidin via both enzyme-linked colorimetric and Quantum Dot/COPAS assays.

Journal Article↗

PubMed2002

Versatile "traceless" sulfone linker for SPOS: preparation of isoxazolinopyrrole 2-carboxylates.

A five-step solid-phase synthesis of isoxazolinopyrrole-2-carboxylates (6) that employs a traceless sulfone linker strategy is reported. Resin-bound diene 4, obtained by acetylation and concomitant beta-elimination of acetate from resin-bound allylic alcohol 3, underwent regioselective 1,3-dipolar cycloadditons with nitrile oxides. Formation of the pyrrole products in a resin-releasing strategy was performed by pyrrole annulation with alkyl isocyanoacetates, which react with the vinyl sulfone moiety to generate the target isoxazolinopyrrole-2-carboxylates (6). Use of this chemistry afforded eight isoxazolinopyrrole-2-carboxylates in 6-24% overall yields from polystyrene/divinylbenzene sulfinate 1.

Journal Article↗

PubMed2002

C-O bond formation by polyketide synthases.

Polyketide synthases (PKSs) assemble the polyketide carbon backbone by sequential decarboxylative condensation of acyl coenzyme A (CoA) precursors, and the C-C bond-forming step in this process is catalyzed by the beta-ketoacyl synthase (KS) domain or subunit. Genetic and biochemical characterization of the nonactin biosynthesis gene cluster from Streptomyces griseus revealed two KSs, NonJ and NonK, that are highly homologous to known KSs but catalyze sequential condensation of the acyl CoA substrates by forming C-O rather than C-C bonds. This chemistry can be used in PKS engineering to increase the scope and diversity of polyketide biosynthesis.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗

PubMedDate not supplied

Solid-phase synthesis of an isoxazolinopyrrole library.

A four-step solid-phase synthesis of isoxazolinopyrroles 8 that employs an acid-labile 2-(4-formyl-3-methoxyphenoxy)ethyl polystyrene HL resin 1 is reported. Resin-bound vinyl sulfone 5 is obtained by DIC coupling with acid 4, which was in turn synthesized in solution phase by a regioselective nitrile oxide 1,3-dipolar cycloaddition. The resin-bound pyrrole 7 was synthesized on solid phase by pyrrole annulation with various isocyano derivatives and potassium t-butoxide in which the sulfone alpha-anion generated by Michael addition gives the desired pyrrole through internal condensation followed by a sigmatropic [1,5]-hydrogen shift. The resulting isoxazolinopyrroles 8 were released from resin 7 by 10% TFA in moderate to excellent overall yields from 2-(4-formyl-3-methoxyphenoxy)ethyl polystyrene HL resin 1.

Journal Article↗